Flow choking plug assembly for nuclear reactor

Abstract

The utility model discloses a choke plug assembly for a nuclear reactor. The choke plug assembly comprises a choke plug connecting frame and a compression cross rod, the choke plug connecting frame comprises a plurality of choke plug rods, a connecting plate and a connecting rod, the choke plug rods are fixedly connected to the connecting plate, and the connecting rod is fixedly connected to the connecting plate; a plurality of groove bodies are formed in the outer side wall of the connecting rod, each groove body comprises an axial groove extending in the axial direction of the connecting rod and a circumferential groove extending in the circumferential direction of the connecting rod, and the axial groove is communicated with the adjacent circumferential groove; the pressing cross rod is provided with a hollow cylinder, and a plurality of claws are arranged on the inner side wall of the hollow cylinder. Wherein the hollow barrel can be arranged outside the connecting rod in a sleeving mode, and the hook claws can move along the corresponding axial grooves and the circumferential grooves so that the hook claws can be clamped in the groove bodies, and connection between the pressing transverse rod and the choke plug connecting frame is formed. When the choke plug assembly is assembled, the whole assembly can be completed through one-time pressing-rotating-loosening process, the process is convenient, fast and efficient, and the assembly procedure of the choke plug assembly can be simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of related components for nuclear reactors, in particular to a choke plug component for a nuclear reactor. Background Art

[0002] The choke plug assembly is a component that mates with the nuclear reactor fuel assembly. Its primary function is to insert choke plugs into all guide tubes within the fuel assembly that do not contain control rods, burnable poison rods, or neutron source rods. This restricts the flow of bypass coolant through the guide tubes and maintains flow balance throughout the fuel assembly core. The choke plug assembly is a stationary device within the fuel assembly. Unless the reactor is shut down for refueling, it remains firmly pressed into the fuel assembly's guide tube channel and does not move relative to the fuel assembly.

[0003] The most common choke assembly structure currently used in engineering is the Fuel-Bearing Plugging Device (International Patent Publication No. ES8703033A1, application date January 16, 1987), invented by EDF (Electricite de France). This traditional choke structure limits bypass flow in the guide tube, but its assembly is complex, requiring a pin to be inserted into the forked screw at the top of each choke rod and then spot-welded to secure each one, resulting in inefficient production.

[0004] Patent CN104900288A discloses "a new type of baffle assembly and radioactive rod for preparing radioactive sources in pressurized water reactors." Its new baffle assembly includes a connecting plate and a stainless steel baffle rod, and also includes a radioactive rod that absorbs neutrons to produce radioactive isotopes. The center guide cylinder and the clamping member in this patent are slidably connected by pins and guide grooves, and the lower end of the center guide cylinder is fixedly connected to the connecting plate. A coil spring is provided on the outside of the center guide cylinder to prevent the clamping member from applying rigid pressure to the connecting plate and causing damage. However, the assembly between the center guide cylinder, the clamping member and the connecting plate in this patent is still cumbersome, and disassembly is even more inconvenient. The disassembly process will cause damage, and production efficiency is low. Utility Model Content

[0005] In order to solve the above problems, the utility model provides a choke plug assembly for a nuclear reactor. The choke plug assembly can be quickly assembled and disassembled, thereby realizing non-destructive and rapid disassembly of the choke plug assembly.

[0006] The utility model aims to provide a choke assembly for a nuclear reactor, comprising a choke connecting frame and a pressing cross bar;

[0007] The choke connecting frame includes a plurality of choke rods, a connecting plate, and a connecting rod, wherein the choke rods are fixedly connected to the connecting plate, and the connecting rods are fixedly connected to the connecting plate;

[0008] A plurality of grooves are formed on the outer side wall of the connecting rod, each of the grooves comprising an axial groove extending along the axial direction of the connecting rod and a circumferential groove extending along the circumference of the connecting rod, wherein the axial groove is connected to adjacent circumferential grooves;

[0009] The pressing cross bar has a hollow cylinder, and a plurality of hook claws are provided on the inner side wall of the hollow cylinder;

[0010] The hollow cylinder can be sleeved on the outside of the connecting rod, and each hook can move along the corresponding axial groove and circumferential groove to clamp the hook in the groove body to form a connection between the clamping cross bar and the baffle connecting frame.

[0011] Optionally, the groove body includes an axial groove and a circumferential groove, one end of the axial groove extends to the end of the connecting rod, and the other end is connected to the circumferential groove, and the end of the groove body is the circumferential groove.

[0012] Optionally, the circumferential groove at the end of the groove body is also connected to a biased groove, which extends along the axial direction of the connecting rod. The biased groove has an extension portion along the axial direction of the connecting rod. The extension portion and the biased groove are located on both sides of the circumferential groove at the end of the groove body, and the hook claw can move in the biased groove and the extension portion.

[0013] Optionally, the hooks are distributed at equal intervals along the circumference of the hollow cylinder, the hooks protrude to the outside of the hollow cylinder, and the ends of the hooks are bent toward the side wall of the hollow cylinder.

[0014] Optionally, four hooks are provided.

[0015] Optionally, a spring is fixedly provided at one end of the compression cross bar, and the spring can be sleeved on the outside of the connecting rod.

[0016] Optionally, the clamping cross bar, the hook claw and the spring are an integrated structure.

[0017] Optionally, the compression crossbar is a special-shaped crossbar.

[0018] Optionally, the choke rods are arranged in parallel, and at least two of the choke rods have a hollow structure inside, and the hollow structure is built into the irradiation sample.

[0019] Optionally, the choke rod, the connecting plate and the connecting rod are an integrated structure.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] 1) When assembling the choke assembly, the connection method no longer requires multiple small parts such as nuts and pins, nor does it require individual welds to prevent loosening. The entire assembly is completed in a single "press-twist-release" process, which is more convenient, fast, and efficient, simplifying the choke assembly process.

[0022] 2) Without affecting the normal operation of the core and ensuring the basic current limiting function of the choke plug assembly, the internal cavity of the choke plug rod is used to provide a carrying space for irradiated samples, which is conducive to the full utilization of the irradiation resources within the reactor and can provide a new irradiation test channel for new materials.

[0023] 3) The choke assembly adopts an innovative multi-body integrated design, which greatly reduces the number of parts and can significantly shorten the manufacturing process and production cycle of the entire choke assembly.

[0024] While retaining the flow-limiting and clamping functions of the choke plug assembly, the choke plug connecting frame is an integrated casting or additively printed part, which can avoid the risk of small parts falling off and into the coolant circuit, and protect the components within the stack from impact and wear caused by falling foreign objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the examples. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0026] Figure 1 This is a schematic structural diagram of the baffle assembly of the present utility model;

[0027] Figure 2 It is a partial cross-sectional view of the baffle assembly of the utility model;

[0028] Figure 3 This is a schematic diagram of the structure of the compacting crossbar, hook claw and spring in accordance with the present invention;

[0029] Figure 4 This is a schematic diagram of the baffle connecting frame of the present invention.

[0030] The components and corresponding marks in the accompanying drawings are:

[0031] 1-compression crossbar, 2-choke connecting frame, 20-connecting rod, 21-connecting plate, 22-choke rod, 200-axial groove, 201-biased groove, 2011-extension part, 202-circumferential groove, 3-irradiation sample, 4-claw, 5-spring, DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the utility model will be further described in detail below in combination with embodiments and drawings, the illustrative embodiments of the utility model and its description are only used to explain the utility model, and do not serve as the limitation of the utility model.

[0033] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the utility model. However, it will be apparent to one ordinarily skilled in the art that the specific details need not be employed to practice the utility model. In other embodiments, well-known structures, circuits, materials or processes are not specifically described in order to avoid obscuring the utility model.

[0034] Throughout the specification, references to "one embodiment", "an embodiment", "one example", or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the utility model. Therefore, the appearance of the phrases "in one embodiment", "in an embodiment", "in one example", or "in an example" in various places throughout the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments or examples. In addition, the skilled person in the art will appreciate that the drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Embodiment 1:

[0036] As shown in the figure, a flow blocking plug assembly for nuclear reactor comprises a flow blocking plug connecting frame 2 and a pressing cross rod 1. Figures 1 to 4 The flow blocking plug connecting frame 2 comprises 24 flow blocking plug rods 22, one connecting plate 21 and one connecting rod 20.

[0037] The axes of the 24 flow blocking plug rods 22 are parallel to each other, and are positioned and connected through the connecting plate 21.

[0038] The connecting plate 21 is located at the top of the flow blocking plug rods 22 and is perpendicular to the axial direction of the flow blocking plug rods 22, and the connecting plate 21 is provided with eight through irregular water flow holes, which can realize the minimization of water flow resistance while connecting the 24 flow blocking plug rods 22.

[0039]

[0040] ​The connecting rod 20 is a cylindrical structure fixed above the connecting plate 21, with the central axis of the connecting rod 20 coinciding with the central axis of the connecting plate 21. The cylindrical outer wall of the connecting rod 20 is provided with multiple grooves, each of which includes an axial groove 200 extending along the axial direction of the connecting rod 20 and a circumferential groove 202 extending along the circumference of the connecting rod 20. The axial grooves 200 and the circumferential grooves 202 are arranged alternately, and the axial grooves 200 are connected to adjacent circumferential grooves 202. The ends of the grooves can be either axial grooves 200 or circumferential grooves 202.

[0041] In this embodiment, four slots are preferably provided, each of which preferably includes an axial slot 200 that is also a vertical slot and an axial slot 200 that is also a horizontal slot. One end of the axial slot 200 extends to the end of the connecting rod 20, and the other end is connected to the circumferential slot 202, which is located at the end of the slot. In this way, each vertical slot moves horizontally to the right or left when it extends downward to a specific height.

[0042] The compression crossbar 1 is a shaped beam structure with a hollow cylinder in the middle, forming a circular structure that is used to enclose the top of the connecting rod 20 of the choke connector 2. Multiple hooks 4 are provided on the lower inner wall of the hollow cylinder, preferably with four hooks 4 evenly distributed along the 0° to 360° angle, corresponding to the number of grooves. The dimensions of the hooks 4 match those of the axial groove 200 and the circumferential groove 202, allowing the hooks 4 to slide within the corresponding axial groove 200 and circumferential groove 202.

[0043] During assembly, the clamping crossbar 1 is pressed down to allow the hook 4 to enter the axial groove 200, and then the hook 4 is rotated to enter the circumferential groove 202. The same method is used to repeatedly press down and rotate until the hook 4 enters the circumferential groove 202 or the axial groove 200 at the end of the groove body. In this embodiment, it is preferred to perform one press down and one rotation, and the hook 4 finally enters the circumferential groove 202 at the end of the groove body. In this way, the connection between the clamping crossbar 1 and the baffle connecting frame 2 can be achieved by the "press down and rotate" method. The assembly process is convenient, fast and efficient, and the disassembly process is also convenient and fast. The disassembly process is non-destructive and does not require the traditional method of inserting pins and spot welding one by one for assembly, which greatly improves production efficiency.

[0044] Example 2:

[0045] like Figures 1 to 4As shown, on the basis of Example 1, the circumferential groove 202 located at the end of the groove body is also connected to the bias groove 201, and the bias groove 201 extends along the axial direction of the connecting rod 20. The bias groove 201 has an extension portion 2011 extending along the axial direction of the connecting rod 20. The extension portion 2011 and the bias groove 201 are located on both sides of the circumferential groove 202 at the end of the groove body, forming a structure in which each vertical groove moves horizontally to the right or left when extending downward to a specific height and then continues to extend downward, and the top of each right or left horizontal groove protrudes upward to form a card pit, namely the extension portion 2011. The hook claw 4 can slide in the bias groove 201 and the extension portion 2011, and the card pit is used to clamp and accommodate the four hook claws 4.

[0046] In this embodiment, the hook 4 protrudes to the outside of the hollow cylinder, and the end of the hook 4 is bent toward the side wall of the hollow cylinder to form a "J" shape.

[0047] A spring 5 is fixedly provided at one end of the compression cross bar 1 . The spring 5 is a right-handed spring 5 . The bottom of the spring 5 is a free end, and the end is ground flat. The spring 5 can be sleeved on the outside of the connecting rod 20 .

[0048] During assembly, the compression crossbar 1 is pressed downward to allow the hook 4 to enter the axial groove 200. The hook 4 is then rotated and released, ultimately retaining the hook 4 in the extension 2011. This "press-rotate-release" method allows for quick and efficient assembly. The extension 2011 and spring 5 cooperate to securely retain the hook 4, achieving a reliable connection. During operation within the stack, the hook 4 slides up and down within the deflected groove 201 and extension 2011 on the outer wall of the connecting rod 20 due to thermal expansion, radiation growth, and flow fluctuations. The deflected groove 201 and extension 2011, in conjunction with the spring 5, enable axial relative displacement between the compression crossbar 1 and the choke connector 2, maintaining a tight and secure connection throughout this movement. Thus, while the fuel assembly undergoes compression, if its length changes due to radiation growth, thermal expansion, or flow fluctuations, the choke will achieve relative displacement through the upward and downward sliding of the hook 4 in the deflected groove 201, thus satisfying the requirements for normal fuel assembly deformation.

[0049] Furthermore, in this embodiment, the clamping cross bar 1 and the hook claw 4 and the spring 5 are an integrated structure, forming an integrated structural part, which can be integrated into a casting or 3D printing process and completed in one step. This greatly improves the manufacturing and assembly efficiency and significantly reduces the number of parts in the baffle assembly.

[0050] Example 3:

[0051] This article will also consider the potential application of choke assemblies in irradiation testing. The current slow progress in irradiation testing has severely hampered the nuclear grade assessment and rapid commissioning of new materials. This difficulty stems from two main factors: 1. The irradiation testing cycle is long, lasting one to two years, and is expensive, resulting in a severe shortage of irradiation testing resources in China at this stage; 2. Although the neutron irradiation rate is highest in the active section, most of the components in this section are critical and important. If new materials are directly placed in the active section for irradiation, it is likely to pose a significant operational risk. Therefore, a relatively low-risk irradiation testing location is urgently needed. Considering these two points, the inventors believe that the choke assembly may be one of the high-quality carriers for irradiated materials in the future, as it can be placed into the reactor with the fuel assembly, is close to the active section, is a non-critical component, is easy to replace, and is relatively inexpensive.

[0052] Based on the above considerations, and building on Example 2, this embodiment incorporates at least two choke rods 22 with a hollow interior, cylindrical in shape. This space allows for the pre-loading of small irradiation samples 3 of various new materials, such as molybdenum, rhenium, and zirconium alloys, during processing. These samples can be loaded into the stack along with the choke assembly to facilitate in-stack irradiation of the new materials. After the choke assembly is recovered, the small samples can be removed and tested for irradiation effects. During stack loading, these 24 choke rods 22 are inserted into the corresponding 24 guide tubes on the fuel assembly. This provides a convenient loading channel for new materials for in-stack irradiation testing, without affecting normal core operation.

[0053] Furthermore, during assembly of the conventional choke plug assembly, the choke rods 22 must be mated to the connecting plate 21 using nuts and screw structures at the top of each choke rod 22, and then pins are inserted into the forked screws at the top of each choke rod 22 and spot welded one by one. This choke plug assembly is relatively complex, requiring not only the individual assembly of the 24 choke rods 22 but also multiple spot welding operations. This increases the number of parts and the number of connection steps between the parts, resulting in low production efficiency.

[0054] Based on the above, in this embodiment, the choke rod 22, the connecting plate 21, and the connecting rod 20 are arranged as an integrated structure to form an integrated structural part, which can be processed and formed in one go by an integrated casting or 3D printing process, greatly improving the manufacturing and assembly efficiency and significantly reducing the number of parts in the choke assembly.

[0055] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above are only specific implementation methods of the utility model and are not used to limit the scope of protection of the utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A choke plug assembly for a nuclear reactor, characterized in that: It comprises a baffle connecting frame (2) and a pressing cross bar (1); The choke connecting frame (2) comprises a plurality of choke rods (22), a connecting plate (21), and a connecting rod (20); the choke rods (22) are fixedly connected to the connecting plate (21); and the connecting rods (20) are fixedly connected to the connecting plate (21); A plurality of grooves are formed on the outer side wall of the connecting rod (20), each of the grooves comprising an axial groove (200) extending in the axial direction of the connecting rod (20) and a circumferential groove (202) extending in the circumferential direction of the connecting rod (20), wherein the axial groove (200) is connected to an adjacent circumferential groove (202); The pressing cross bar (1) has a hollow cylinder, and a plurality of hook claws (4) are provided on the inner side wall of the hollow cylinder; The hollow cylinder can be sleeved on the outside of the connecting rod (20), and each hook (4) can move along the corresponding axial groove (200) and circumferential groove (202) to clamp the hook (4) in the groove body, thereby forming a connection between the clamping cross bar (1) and the baffle connecting frame (2).

2. A choke plug assembly for a nuclear reactor according to claim 1, characterized in that: The groove body comprises an axial groove (200) and a circumferential groove (202); one end of the axial groove (200) extends to the end of the connecting rod (20), and the other end is connected to the circumferential groove (202); the end of the groove body is the circumferential groove (202).

3. The choke plug assembly for a nuclear reactor according to claim 2, characterized in that: The circumferential groove (202) at the end of the groove body is also connected to a biased groove (201), the biased groove (201) extends along the axial direction of the connecting rod (20), and the biased groove (201) has an extension portion (2011) along the axial direction of the connecting rod (20). The extension portion (2011) and the biased groove (201) are located on both sides of the circumferential groove (202) at the end of the groove body, and the hook (4) can move in the biased groove (201) and the extension portion (2011).

4. A choke plug assembly for a nuclear reactor according to claim 3, characterized in that: The hook claws (4) are distributed at equal intervals along the circumference of the hollow cylinder, the hook claws (4) protrude to the outside of the hollow cylinder, and the ends of the hook claws (4) are bent toward the side wall of the hollow cylinder.

5. The choke plug assembly for a nuclear reactor according to claim 3, characterized in that: Four hook claws (4) are provided.

6. The choke plug assembly for a nuclear reactor according to claim 3, characterized in that: A spring (5) is fixedly provided at one end of the compression crossbar (1), and the spring (5) can be sleeved on the outside of the connecting rod (20).

7. The choke plug assembly for a nuclear reactor according to claim 6, characterized in that: The pressing cross bar (1), the hook claw (4) and the spring (5) are an integrated structure.

8. The choke plug assembly for a nuclear reactor according to claim 1, characterized in that: The pressing cross bar (1) is a special-shaped cross beam.

9. The choke plug assembly for a nuclear reactor according to claim 1, characterized in that: The choke rods (22) are arranged in parallel, and at least two of the choke rods (22) have a hollow structure inside, and the hollow structure is built into the irradiation sample (3).

10. The choke plug assembly for a nuclear reactor according to claim 1, characterized in that: The choke rod (22), the connecting plate (21), and the connecting rod (20) are an integrated structure.

Images